Common Alder

Alnus glutinosa

Common Alder

Closely related to the birch tree, the alder is most commonly planted next to rivers and streams as it can firm the water's edge and thrives in wet conditions. If the roots grow into the water, then an alder tree can provide some very welcome shelter for fish. One of the most notable properties of the alder is that it has nodules which harbour nitrogen-fixing bacteria. The bacteria convert nitrogen in the air to a usable form and the alder tree provides the bacteria in the soil with carbon. This symbiosis has developed in Britain over centuries to fix nitrogen and encourage soil-improving micro-organisms which makes Alnus glutinosa an excellent choice for difficult land. Unusually for a deciduous tree, the alder produces its seed in small cones but it is not as traditionally beautiful as some other native trees and an Alnus is best used to add interest to ground which is simply too wet and inhospitable for other native trees.

All our trees and shrubs are grown to be the perfect size for best establishment. For most species this can range from 20-60cm above the root plug. If you would like to discuss specific sizes, please contact us.

Folklore of Alder Trees

If you have ever taken a walk in an alder forest, then much of the dark and mystical legend surrounding alder is immediately apparent. An alder forest grows in damp, marshy ground and the crown of the tree is high, wide and dense, covering the area in darkness. Anyone with the misfortune to walk in these woodlands will have a foreboding, spooky experience which provided perfect hiding places for fugitives, so alder trees were always associated with secrecy and hiding. When cut, the alder wood turns an orange-red colour, which led our forebears to think that the wood was bleeding before it darkened. The Anglo-Saxons believed that this darkened wood attracted wood worm and so put an alder spring near furniture so that the beetles would lay their eggs in the alder sprig and not in the furniture - modern scientists actually think this might be true!